Double quine

Write a program A which when run emits to STDOUT a program B in the same language. Program B when run should then emit the source of A.

The source of A and B must not be identical–that is, A alone must not be a quine. Trailing whitespace is ignored in this comparison, and in the comparison of B’s output and A.

Judge

(async function*(context: Context): Challenge {
  const run_1 = (await context.run());
  yield run_1.assert((e)=>new TestCase('A should not be the same as B', !eqIgnoreTrailingWhitespace(e, context.code) ? 'Pass':'Fail', {"Text": "A and B must not be the same, or this task would be extremely trivial."}));
  const run_2 = (await context.runCode(run_1.text));
  yield run_2.assertEquals(context.code).setName("B's output should be the same as A");
  return context.noFailures();
})

Example Code

function A() {return A + "\nconsole.log(A + '\\nconsole.log(A())')" }
console.log(A())